Power transmission



n15 w. GILFILLAN ETAL POWER TRANSMISSION I Original Filed Sept. 20. 1940 5 Sheets sheet l VIII Ill] MMJM r 0. MW ma 1% ATTORN EY 0a. 15, 1946. H, GILHLLAN 'ETAL 2,409,557

l'fOWER TRANSMISSION Original Filed Sept. 20. 1940 5 Sheets sheet 2 INVENTOR 5 //)7r M 62272 [[417 ATTORNEE Oct. 15, 1946. H. w. GILFILLAN ETAL 2,409,557

POWER TRANSMISSION Original Filed Sept. 20, 1940 5 she'ets sheet 3 H. W. GILFILLAN ETAL POWER TRANSMISSION Original Filed Sept. 20. 1940 5 Sheets-Sheet 4 Z gdr 1. 25 5- /i im M flair Km;

ATTORNEY:-

v Oct. 15, 1946. H. w. GILFIILLAN ETAL 2,409,557

POWER TRANSMISSION Original Filed Sept. 20, 1940 5 ShgetsSheet 5 IIIIIIIIII'.

V Il/II/ He; I J 21, BYE 1 74! 1. 34:11.25 M mmm w ATTORNEY Patented Oct. 15, 1946 POWER TRANSMISSION Henry W. Gilfillan, Detroit, and Edgar L. Bailey,

Birmingham, Mich., assignors to Chrysler Corporation, Highland Park, Mich., a corporation of Delaware Original application September 20, 1940, Serial No. 357,528. Divided and this application January 1, 1942, Serial No. 425,292

18 Claims. 1

This invention pertains to automotive power transmissions and this application is a division of our copending application, Serial No. 357,528, filed September 20, 1940.

More particularly, the invention relates to a power transmission of the electrodynamic type wherein a planetary gearset is disposed in combination with electromagnetic brake and clutch devices of the eddy current type; the arrangement being such that torque multiplication is obtained through the planetary gearset for starting and acceleration of the vehicle, the sun gear being held against rotation by operation of the eddy current brake, while the planetary gearset is locked up in one to one ratio at the end of the acceleration period by operation of the eddy current clutch, suitable control mechanism being provided.

It is the principal object of the present invention to provide an improved automatic power transmission suitable for use in motor vehicles.

An additional object is to provide in such a transmission simplified mechanism adapted for automatic control making possible the elimination of many parts now found in conventional automobile power transmissions without, however, eliminating or sacrificing any of the speed or acceleration characteristics thereof.

A further object is to provide a transmission in which the conventional mechanical clutch is eliminated.

A still further object is to provide an improved eddy current clutch wherein the field coil and the greater portion of the iron mass remains stationary during operation whereby the rotating mass is considerably reduced and the efficiency raised.

A still further object is to provide a combined eddy current clutch and brake device having a stationary unitary field structure.

A still further object is to provide a transmismission of the aforesaid type wherein the electrical unit is required to transmit only a minor portion of the engine torque thereby permitting the size of this unit to be reduced with consequent reduction in weight and cost.

A still further object is to provide improved means for cooling the electrical unit.

Other objects and advantages of the invention will become apparent from the following description.

In the drawings which accompany the description, and which illustrate a preferred embodiment of the invention,

Fig. 1 is a diagrammatic showing of the power plant and drive mechanism of a vehicle incorporating the present invention.

Fig. 2 is a side elevation of the power plant and transmission mechanism.

Fig. 3 is a sectional view along line 3-3 of Fig. 2.

Fig. 4 is a sectional view along line 4-4 of Fig. 2.

i Fig. 2.

Fig. 6 is a sectional view along line 6-6 of Fig. 5.

Fig. 7 is a longitudinal sectional view of the rear gearbox unit of the transmission.

Fig. 8 is an elevational sectional view of the forward electrical unit of the transmission, certain of the parts being shown in section.

Fig. 9 is a fragmentary plan view taken as indicated by the arrows 99 in Fig. 8, parts being broken away where necessary to show details thereof.

Fig. 10 is a sectional view along line lO-lll of 5 is a sectional view along line 55 of Fig. 8.

Fig. 11 is a sectional view along line H-ll of Fig. 8.

Fig. 12 is a sectional view along line l2l2 of Fig. '7.

Fig. 13 is a diagrammatic view on a reduced scale of the Fig. 12 shift mechanism, the view being taken as indicated in the arrows l3l3 on Fig. 12, and the parts being shown in neutral position.

Fig. 14 is a view of the Fig. 13 parts in one of their shifted positions.

Fig. 15 is a wiring diagram of the transmission.

Fig. 16 illustrates a modification of the wiring diagram of Fig. 15.

Fig. 17 is diagrammatic illustration of the eddy currents flowing in the clutch armature during operation of the clutch.

Fig. 18 is a diagrammatic illustration of the flux flow between the teeth of the brake during operation thereof.

Referring to the drawings wherein reference characters are used to designate corresponding parts referred to in the following description, Fig. 1 illustrates a typical arrangement of transmission mechanism in a vehicle embodying the present invention. The vehicle engine A is coupled to the driving wheels IU of the vehicle through a pair of torque multiplying units B and C; the unit B consisting of an electrically controlled underdrive unit illustrated in detail in Fig. 8 and the unit C consisting of a manually controlled high, low and reverse gearbox illustrated more fully in Fig. 12.

The output shaft l l of unit C is connected by means of the usual propeller shaft with the differential gearbox l3, which in turn, drives the axle shafts l4.

Referring for the moment to Figs. 8 to 11, inclusive, l5 designates the rear end of the crankshaft of engine A, which crankshaft is bolted by bolts I5 to the usual flywheel ll. The latter is provided with the familiar ring gear l8 which forms part of the engine starting mechanism.

Secured to flywheel H by bolts I9 is an annulus gear 29 which forms part of a planetary gearset which is generally designated by the letter D. The gear meshes with a plurality of planet gears 2| carried for rotation on a carrier 22 through the intermediary of a plurality of axles 23. The carrier 22 extends forwardly into the hollow portion 24 of crankshaft l5 and is supported therein by an anti-friction thrust bearing 25.

Carrier 22 is splined at 26 to a shaft 2! on the rear end of which is integrally formed the input pinion 28 of the rear gearbox C. Also meshing with planet gears 2| is a sun gear 29. The latter is provided with a rearwardly extending hub 39 and is rotatably mounted on the shaft 2. by a pair of antifriction bearings 3|, 32, an abutment ring 33 maintaining the parts in their correct positions.

Bolted to the flywheel I! at 34 is an annularly shaped member 35 of iron or other suitable magnetic material which constitutes the driving member of the electrical eddy current operated clutch, generally referred to by the letter E. The memher 35 has cooling fins 36 machined in the outer surface thereof, the purpose of which will be brought out later on in the description.

Fixed to the sun gear hub 39 by bolts 31' is a spider 38 which constitutes the driven member of the clutch. The spider 38 is provided with a built-up cylindrical inductor portion having alternate magnetic and non-magnetic sections. Fig, 8 illustrates a preferred form of spider which consists of a drive portion 39 of iron to which is welded or otherwise suitably fixed a non-magnetic ring 40 of stainless steel, brass, or the like. To the ring 40 an iron ring 4| is fixed, followed by a second non-magnetic ring 42, the latter in turn being followed by a second iron ring 43. The cylindrical portion 39 of the spider driving portion 39 and the iron ring 4| are provided on their outer surfaces with alternately disposed teeth 44 (see Figs. 9 and 10) the purpose of which will soon become apparent.

The housing for the underdrive unit B is formed of two casing members 45 and 46 fastened together by a plurality of cap screws one of which is shown at 41. Attached to the casing 46 by a plurality of screws such as that shown "at 48 is a built-up iron core member 49. The core member consists of a substantially U -shaped portion 50 provided with radially inwardly extending teeth 5|, to which is secured a portion 52 having radially outwardly extending teeth 53, and a portion 54 spaced from the portion 52 in the vicinity of the ring 40 by a similar non-magnetic ring 55, the whole assembly being retained in place by the annular portion 56 which is keyed to the portion 50 by a key 51. A pair of field coils 5B and 59 respectively are carried by the core assembly in the relationship shown in Fig. 8. The coils are adapted for excitation from the regular vehicle battery through suitable connections (not shown), the excitation thereof being under the control of apparatus about to be described.

Casing 48 is provided with a plurality of holes for the reception of screens such as those shown at 6B and El through which cooling air is circulated as indicated by the arrows in Fig. 8. A stamped air impeller element 52 is attached to the clutch spider 38 and is provided wi 11 integral vanes 53 for creating circulation. The clutch drive member 35 is provided with circumferentially spaced holes 64 which permit passage of air outwardly thereof.

The rotating parts of the underdrive unit B are lubricated by oil from gearbox C (which is partially filled with lubricating oil as is common practice in the art) which travels through passage 65 of shaft 27 thence by way of bearing 25,

gearset D and passages 66 and 67 to the hollow space 68 from Where it can flow back to gearbox C through bearing 69. Suitable seals 67a and 68a are provided to confine the lubricant to the necessary path, the latter seal being placed between the sun gear hub 36 and a forwardly extending quill 69a carried by the rear wall of casing 45.

The planet gearing D may have any desired ratio, the one illustrated being constructed and arranged to provide a 1:38 to 1 speed reduction between crankshaft I5 and shaft 2'? when sun gear 29 is held against rotation. The ratio 1:38 to 1 is suitable for both acceleration at low speeds and for kickdown acceleration of the vehicle at relatively high speeds, and with this ratio it is apparent that only a portion of engine torque (approximately 40%) is transmitted through the electrical unit, the rest being transmitted directly through the mechanical gear connection.

In the operation of the device as so far described, rotation of the engine crankshaft |5 in the usual clockwise direction will cause corresponding rotation of annulus gear 20. If field coils 58 and 59 are de-energized, the reaction of shaft 21 (which is assumed to be connected to the vehicle drive wheels) will cause sun gear 29 and spider 33 to be rotated in reverse direction at approximately 2 /2 times crankshaft speed, no torque being transmitted to shaft 21.

Under such conditions, if field coil 59 is energized, magnetic flux will flow in a circular path through the portions 50. 52 and of iron core 49. This flux will flow across the air gap between teeth 5| and 53 and to a much lesser extent across the relatively wide gap between adjacent pairs of radially aligned teeth. As illustrated in Figs. 9 and 11, the portion 43 of spider 39 has teeth 76 formed thereon. These teeth (or poles) are spaced from one another in such manner that they will align radially with the teeth (or poles) 5| and 53 of the core 49 and with the spaces between teeth 5| and 53 respectively in alternate fashion during rotation of spider 38.

Now it is obvious that when teeth 5|, l9 and 53 are all in radial alignment, the flowing in core 49 around coil 59 will flow through the iron of the teeth 19 and thus will encounter relatively low resistance to flow, the reluctance of the air gap between oppositely disposed teeth 5| and 53 having been reduced by the iron in teeth ll). Correspondingly, when the teeth l5 are radially aligned with the spaces between the respective sets of teeth 5| and 53, the flux will encounter relatively great resistance to flow because of the reluctance of the large air gap between teeth 5| and 53. In other words, the flux is at a maximum when teeth 5|, Til and 3 are aligned, and at a minimum when teeth 79 are out of alignment with teeth 5| and 53.

Accordingly, during rotation of spider 33 the flux will fluctuate between maximum and minimum values, the frequency thereof being determined by the speed of rotation of the spider, and

eddy currents will be induced in teeth 5|, and 53 and likewise in the core 49. The eddy currents flow in a direction perpendicular to the path of the flux ranging in voltage in accordance with the speed of the spider, and induce a flux of their own which reacts with the main flux and tends to prevent relative rotation between the spider 38 and core 49. This is in accordance with Lenzs law which states, in effect, that change in magnitude of a magnetic field induces a current so directed that its magnetic effect tends to oppose the magnetic change which produced it.

The effect of the flux flowing through the teeth 51, I8 and 13 then, will be to slow down the reverse rotation of the spider 38 and cause it to stop whereupon the direct magnetic pull of the flux will hold it stationary. With the spider 38 thus held against rotation by the magnetic pull across teeth 5|, 53, the planetary gearset D will, through reaction on sun gear 29, transmit a torque multiplying drive to shaft 21 whereupon the vehicle will be accelerated in underdrive at a speed dependent upon the speed of the engine A.

It will be appreciated that torque will be imposed on shaft 21 from the instant that spider 38 begins to slow down, therefore the vehicle will be started in a smooth and gradual manner, the brake F functioning as an exceptionally smoothacting clutch.

Acceleration of the vehicle in underdrive may be continued as long as desired and when a sufiicient speed has been attained, coil 59 may be deenergized and coil 58 energized whereupon brake F will release spider 38 and clutch E will magnetically couple the spider 38 to the driving member for forwardrotation therewith.

Energization of field coil 58 causes flux to flow through portions 56 and 54 of core 49, thence across the narrow air gap 12, through portion 39 of spider 38, across air gap 13 into the driving member 35 and back to portion 56 through portion 41 of the spider and 52 of the core, the air gaps i2 and 13 also bein crossed on the return circuit. The non-magnetic rings and 55 assist in confining the. flux to a definite path and the non-magnetic ring 42 helps to separate the fiux circuit of coil 58 from that of coil 59 and viceversa.

As illustrated in Figs. 8 and 10, the radially adiacent surface portions of the core 49 and spider 38 that form the magnetic circuit for the flux produced by coil 58 are smooth. No eddy currents will therefore be induced by reason of the relative rotation of these two parts and the air gap 72 may be made extremely narrow (in the order of two or three thousandths of an inch) thereby providing as low reluctance as possible. As can be more clearly seen from Fig. 9 and the diagram of Fig. 17, the teeth 44 on portions 39' and 4| of the spider are alternately arranged. This is for the purpose of providing an easier path of flow for the eddy currents induced by the teeth. If the teeth were disposed opposite one another high current densities would result at the inner tips thereof because of the fact that opposing voltages in juxtapositioned teeth would crowd the currents traveling in each direction into a comparatively small volume of iron.

Energization of coil 58 then produces flux at high density which crosses the air gap 13 from the teeth 44 to the driving member 35. Very little flux enters the member 35 at points between the teeth 44 therefore, there exist in the member 35 alternate regions of high and low flux density.

When the members 35 and 38 are rotating relatively to one another a point on the member 35 moves alternately through regions of high and low flux density, thus the flux flowing through said point varies in magnitude and eddy currents are induced. These eddy currents produce an opposing flux which, in accordance with Lenzs law, tends to oppose relative rotation of the members 35 and 38.

The member 38 therefore will tend to approach the speed of the driving member 35 and to rotate at synchronous speed therewith, whereupon the planetary gearset D will be locked up as a unit and drive will be transferred from flywheel l! to shaft 2"! at one to one ratio. In practice, the spider 38 never quite reaches the speed of member 35, there always being present a certain amount of slip which varies with the speed and torque, but is small (in the order of three per cent) at cruising speeds.

During operation of the underdrive unit there is necessarily a considerable amount of heat generated. The air impelling vanes 38 on the member 35, which is always rotating at engine speed, and the vanes 63 on the spider, provide continuous circulation of air through the housing; the air entering through the screen 68 and flowing out through the screen 6| as indicated by the arrows in Fig. 8.

It will be noted from Fig. 11 that the teeth 5!, 53 and 18 are chamfered at their trailing edges and the reason for this will be made clear by reference to Fi 18 when a single pair of teeth, 5! and 18, are diagrammatically represented. It is well known that magnetic flux leaves and enters a pole tip at right angles to the surface thereof, providing of course, that infinite permeability of the iron is assumed. The attractive force of the flux is in the direction thereof and is proportional to 8 A where B represents the flux density and A the area over which it exists. It is therefore evident that only the flux which strikes the pole (or tooth in this case) at right angles to the radial surface thereof is useful in producing a tangential force, the flux passing between circumferential surfaces producing only a radial force which is not useful.

By providing chamfered tips as shown in the drawings, practically all of the fiux passing be tween the teeth is useful. Although the flux, and consequently the force F, is perpendicular to an inclined portion of the teeth, there is present a tangential component Ft, which is large. It is also apparent that the flux density along the chamfered portions decreases rather slowly, which is not the case with fiat teeth, therefore the value of B will be large over a comparatively larger area than is the case with fiat teeth.

Referring now to Figs. 1 to '7, inclusive, and Figs. 12 to 16, inclusive, it will be seen that the shaft 2!- extends rearwardly into the housing M of the gearbox C in which it terminates in a coneshaped clutch portion I5. A hollow portion 16 provides space for the roller bearing '11 which pilots the forward end of the tail shaft I i. Lubricant is circulated through the gears, bearings, etc., through suitable holes which connect with the central bore 18 of shaft II.

The pinion 28 is the input element of the box 0 and meshes with a gear '19, the latter being one of a cluster rotatably carried on a countershaft 80. The cluster also includes a gear 8| which meshes with the low speed driven gear 82, and

a gear 83 which is adapted to be engaged by an idler gear 85 for providing reverse drive, the gear 85 simultaneously meshing with the gear 83 and a gear 84 splined at 86 on shaft II.

The shaft 2'! is formed with a set of clutch teeth 81 which are adapted for engagement by complementary internal clutch teeth 80 formed in clutching sleeve 89, the latter being slidable on a hub 90 which is splined at 9| on shaft I I. Suitable blocker synchromesh mechanism 92 is provided to facilitate smooth and noiseless engagement of the sleeve 09 with the teeth 31. Inasmuch as any suitable type of blocker synchromesh may be used, this part of the mechanism will not be described in detail, it being deemed suflicient to briefly refer to the salient parts thereof.

A similar blocker synchromesh mechanism 93 is provided for facilitating meshing of the teeth of sleeve 89 with the clutch teeth 94 formed on low speed gear 82.

The mechanism for shifting sleeve 89 and idler gear 85 to provide two forward speeds and reverse comprises a hand actuated lever 95 (Fig. 4) having a knob 96 at the outer end thereof. The lever 95 is carried by a casing 91 which forms part of the steering column referred to generally by the numeral 98. The casing 91 has separable sections for purposes of assembly and a slot is provided for receiving a ball-shaped enlargement 99 of lever 95. The portion 99 of the lever has a bore I in which a spring pressed detent i0! is disposed. The detent I9I is adapted to engage in an aperture formed in the wall of the slot as shown in Fig. 3.

The steering column includes an outer tube I03 on which the casing 91 is mounted, and an inner tubular steering shaft I54 which carries the steering wheel I05. A tubular shaft 1515 extends longitudinally of the column and is slidably and rotatably supported by the column structure. Mounted in the upper end of the tubular shaft I06 is a sleeve I91, which is welded thereto and extends beyond the upper extremity thereof. A collar I03 is rigidly secured in place on the shaft by a nut I09. The collar I98 is provided with bosses for receiving pins IIO which are carried by the forked inner end portion of the lever 95. The enlarged portion 99 of the lever serves as a fulcrum about which the lever may be oscillated in a vertical plane to shift the shaft I vertically of the steering column. The shaft l06 may be rotated about its axis which is coincident with the longitudinal axis of the steering column by swinging the lever 95 about the axis of the column.

Axial movement of the shaft I05 is transmitted to the selector mechanism in casing I4 by Bowden wire assembly generally designated by numeral III. One end of the Bowden assembly is mounted in the lower portion of a separable coupling I I2 by of which an extension I I3 of the column housing 98 is supported. The lower element of the coupling H2 is provided with an apertured flange H4 in which a metal tube H5 is fixed by means of a threaded fitting I I5. Slidably carried in the tube H5 is plunger III normally urged upwardly of the column by a spring II8 which bears between the plunger and a fitting II9. A flexible cable I20 extends through the plug H9 and is attached to the plunger Ill. The latter bears against aplate I 2I non-rotatably fixed on the lower extremity of the shaft I06 and which extends outwardly of the coupling I I2 through a slot I22 in the side thereof, the slot being approximately twice as wide as ii LI column.

the thickness of the plate I2I for accommodating shifting thereof axially of the column.

The opposite end of the Bowclen wire assembly extends to the cover plate I23 of the housing I4 where it is received by a fitting I24, the flexible cable I20 being attached to a lever I25 swingably mounted at I25. It is apparent that reciprocation of the shaft I06 will cause corresponding swinging of lever I25, the motion being transmitted by the cable I 20.

Rotative movement of the shaft IDS is transmitted to a shift lever I21 by means of a pair of links I29, I29 connected by a bell crank I30, the link I28 being pivoted to the plate I2I by means of a pin I3I. The plate I2I has a cam shaped portion I33 against which a plunger I34 of a switch I35 is adapted to bear. The switch I35 has a pair of terminals I 38, I39 which are adapted to be bridged by the contact member I40 upon movement of plunger I34 under the influence of spring I36 when the plate I2I is in certain positions as will be more fully explained.

The cover I23 (Fig. 12) is provided with a pair of aligned bosses I40, MI in which is mounted a rock shaft I42, a set screw I 43 holding it against displacement. The shift lever I2'I is operatively secured on the top of the rock shaft by a nut I44.

Rockably mounted on shaft I42 is a trunnion element I45 having an integral shift finger I46. The element I45 is rockable about a mounting pin I41 and is biased to the position illustrated by a coiled compression spring I48.

The sleeve 99 and gear 85 are shifted by a pair of shifter forks designated I49 and I50 respectively, lGSe forks being carried by a pair of shiftable rails I5I and I52. The rails are provided with the usual interlocking plunger I53 and detent receiving grooves I54 as illustrated diagrammatically in Figs. 13 and 14.

The shift finger I45 is normally maintained in engagement with the fork I49 by the spring I48, thus the shift mechanism is normally conditioned for effecting a shift of the sleeve 89 upon swinging of the lever 95 about the axis of the steering In order to shift the reverse gear 85 it is necessary to disengage the finger I45 from the fork I49 and engage it with the fork I50 which is accomplished by rocking the lever 95 upwardly resulting in downward movement of plate I2I to the dotted line position of Fig. 5. This. movement of the plate I2I transmits a push to selector lever I25 through the Bowden cable I20. The selector lever I25 is connected inside the casing "I4 by means not shown with a lever I55 which is adapted to push downwardly on finger I46 in response to counterclockwise swinging of lever I25, thereby rocking trunnion member I45 about the pin E41 and against the compression of spring M8. The finger I45 is thereby disengaged from fork I49 and engaged with fork I50 and swinging of the lever 95 away from the driver will rock shaft I42 about its axis and shift idler gear into mesh with gears 83 and 84. Upon return of lever to neutral position, spring I48 will return the parts to the position shown in Fig. 12 and the shift mechanism will again be conditioned for shifting sleeve 89 into engagement with direct drive clutch 31 or low speed drive clutch 94 depending upon the direction of swing of lever 95.

From Figs. 12, 13 and 14 it may be seen that the portion I56 of the shift finger 148 which engages the fork I49 is cam shaped and the slot I51 of the fork which receives the portion I56 is large enough to permit a considerable amount of lost motion of finger I46 before the fork is shifted. This is for the purpose of permitting the lever 95 to be moved back to neutral position from high or low speed position without necessarily moving the sleeve 89, thereby opening the switch I35 (because of the action of the cam I33) without disturbing the osition of the sleeve 89. If, however, it is desired to shift into reverse from high speed for example, which action cannot be accomplished until rail I5I is returned to neutral because of interlock pin I53, see Fig. 14, movement of finger I46 downwardl will automatically cause rail I5I to be returned to neutral because of the engagement of the cam portion of the finger I46 with the right'hand projection I58 of fork I5I. These projections are provided in each side of slot I51 as illustrated and function to return rail I5I to neutral whenever the finger I46 is moved to engage the fork I50. This operation will be more fully explained below.

Referring now to Fig. in conjunction with Figs. 2 and 12, it may be seen that field coils 58 and 5 9 are connected to the vehicle battery I59 through a plurality of control instrumentalities which include a governor controlled switch I68, an accelerator operated switch I6I and a, pedal operated rheostat switch I62, in addition to the aforementioned switch I which is operated by the plate I2I.

The switch I66 is operated by a governor mechanism I63 of any suitable type driven by a shaft I64 from the countershaft cluster gear 83, and is provided with two'sets of terminals adapted to be bridged by a conductor element I64. When the switch I is in low speed condition, as in Fig. I i

15, underdrive coil 59 is connected to battery I59 through wires I61, I68, element I64, wire I69, switch I62, wire I10, switch I35 and wire Ill. The rheostat switch I62 is operated by a pedal I12, which is equivalent in its operation to a conventional clutch pedal. The switch is on when the pedal I12 is released and off when the pedal is fully depressed, intermediate positions of the pedal causing varying amounts of resistance to be introduced into the circuit as can be readily understood from Fig. 15.

When switch I60 is in high speed position, coil 59 may also be energized through switch I6I which is operated by the accelerator pedal I13.

The latter is pivoted at I14 to the vehicle fioor board I15 and is urged to throttle closed position by spring I 16. A link I11 connects the pedal with a lever I18 pivoted at I19 to the lower surface of the floor board. A link I89 transmits swinging motion of lever I18 through a suitable lost motion connection I8I to a throttle valve control lever I62. The latter is adapted to be swung about its pivot until it engages the stop I84 carried by carburetor riser I 83 at which position the throttle valve is wide open. The pedal I13, lever I18 and link I are then adapted to have further movement overtraveling wide open throttle valve position which is permitted by compression of the spring I of the lost motion connector I8 I. This overtravelling movement operates to swing lever I86, which is fixed to lever I18, far enough for finger I89 thereof to engage the operating finger I81 of switch I6I whereupon the switch is closed, thereby completing a circuit from coil 59 to battery I59 through wires I61, I91, terminals-I92, I93 of switch I60, wire I69, switch I62, wire I10, switch I35 and wire I1I.

Whenever switch I6I is closed by the aforesaid overtravel movement of pedal I13, it stays closed until the pedal is returned substantially to, throttle closed position. This is due to the fact that switch I6I is of the snap-over type and finger I99 of lever I86 is purposely positioned so that it will not engage the switch operating finger I81 until the accelerator pedal I13 is fully released. Operation of switch I6I by overtravel operation of the accelerator pedal is commonly referred to as kickdown operation.

The switch I6I is of the double pole, double throw type and when it is open with respect to underdrive coil 59 it is closed with respect to direct drive coil 58. The latter is connected to the battery I59 through wire I94, switch I6I, wire I9I, switch I60, wire I69, switch I62, wire I16, switch I35-and wire I1I. The battery is grounded at I and is shunted by the usual gen erator I96. v 7

Fig. 16 illustrates a modification of the Fig. 15 control circuit, wherein the circuit is altered by substituting a governor controlled rheostat switch I62 for the pedal controlled switch I62. In the Fig. 16 modification, the switch I62 is exactly the same in construction and operation except that it is automatically operated by a governor I91. The latter is intended to be driven by the engine A in any suitable manner, for example, by the generator drive shaft, and functions to open the circuit between wires I69 and I10 gradually when the vehicle comes to a stop and to gradually energize coil 59 when the vehicle is started.

If desired as a safety feature, the regular vehicle ignition switch may be inserted in the circuit of coils 58 and 59 to thereby render the circuits thereto dead unless the ignition switch is on. This feature is omitted from the drawings for the sake of simplicity.

In describing the operation of the drive, let it be assumed that the vehicle is at rest with the engine A idling and the gear shift lever 95 in neutral position. In order to start the vehicle for forward travel, gear shift lever 95 is swung about the axis of the steering column 98 away from the driver, which action causes the sleeve 89 to be' moved rearwardly of Fig. '1 to thereby mesh the teeth thereof with clutch teeth 94 of low speed gear 82. At the same time the accompanying movement of plate I2I permits plunger I34 of switch I35 to move upwardly of Fig. 5 under the influence of spring I36, thereby to bridge switch terminals I38, I39. The cam I33 of plate I2I is so designed that the plunger I34 of switch I35 will be held in switch-open position until the plate I2I has been swung sufiiciently to fully engage the sleeve 89 with the clutch teeth 94 or the clutch teeth 81, as the case maybe. This feature makes it possible to shift the sleeve 89 without clashing of teeth and without the necessity of depressing pedal I12.

Shifting of sleeve 89 then into low speed position causes switch I35 to close, thereupon energizing underdrive coil 59 through wires I61, I68, terminals I65, I66 of switch I60, wire I69, switch I62, wire I10, switch I35 and wire I1I. Under these conditions, the rheostat switch I62 is in the Fig. 15 position with all of the resistance out out of the circuit and the governor controlled switch I69 is in the Fig. 15 position with the movable conductor member I64 bridging the terminals I65, I66 thereof. 4

Depression of the accelerator pedal I13, therefore, will cause the vehicle to be accelerated in a forward direction with the electrical unit B op- 11 vehicle has been accelerated to a speed of approximately 7 M. P. H. the governor mechanism I63 will operate to open the circuit between terminals I65 and I66 of switch IE9 and close the circuit between terminals I92 and I93 thereof. This action of governor I63 will cause underdrive coil 59 to be de-energized and direct drive coil 58 to be energized through wire I94, switch I6I (which is in closed position with respect to coil 58), wire I9I, switch I60, wire I69, switch I62, wire I10, switch I35 and wire IN. The underdrive mechanism B is now operating in direct drive with the planetary gear set D substantially locked up in one to one ratio. This corresponds to second speed position in conventional transmission mechanisms.

Direct drive in gear box C corresponding to third speed position in conventional transmission mechanisms, may now be obtained by swinging gear shift lever 95 about the axis of the steering column 98 toward the driver. As the lever 95 is swung backwardly, the plate I2I moves plunger I34 of switch I35 to switch open position, thereby de-energizing both direct drive coil 53 and underdrive coil 59. At the same time sleeve 89 is moved I out of engagement with clutch teeth 94 and into engagement with clutch teeth 81, thereby stepping up the drive ratio in gearbox C. Inasmuch as both coils 58 and 59 were de-energized by the action of the cam I33 during the time that the shift of sleeve 89 was being made, the load was relieved momentarily from the shaft 21, thereby permitting the sleeve 89 to be shifted without the necessity of depressing peda1 I12. When the shift lever 95 reaches the extremity of its movement to high speed position, which, it would be pointed out, includes the movement necessary to take up the lost motion on finger I46 with respect to slot I51 of shift fork I49, plunger I34 of switch I35 is again permitted to move to switch closed position under e the action of the spring I36 and underdrive coil 59 is again energized. Governor operated switch I60 having again returned to its low speed position during idling of engine A, the vehicle is now in underdrive in unit 13 and in direct drive in gearbox C. This corresponds to third speed position in conventional transmissions.

The car may now be accelerated to a speed of approximately 18 M. P. H. when governor mechanism I63 will operate to open the circuit between terminals I65, I66 of switch I66 and close the circuit between terminals I 92, I 93 thereof, whereupon underdrive coil 59 will be ole-energized and direct drive coil 58 will be energized in the manner explained above.

I63 operates at a higher speed when gearbox C is in high speed position due to the fact that the governor is driven from counter-shaft cluster gear 83 which, of course, rotates slower when gearbox C is in high speed position for a corresponding car speed. The difference in speed being in accordance with the step-up in ratio. The vehicle under these conditions is being driven in direct drive in both units B and C, this condition being equivalent to overdrive in conventional transmis slons. It is intended to provide a rear axl ratio of approximately 3.2 to 1, thereby obtaining the advantages usually obtained by the use of an overdrive mechanism.

With such a rear axle ratio it is, of course, obvious that the accelerating characteristics of the car will be sluggish and provision is made for an instantaneous return to underdrive in unit B when rapid acceleration is desired as, for example,

The governor mechanism when passing cars at speeds above the operating speed of governor I 63 or when climbing hills.

Return to underdrive in unit 13 is accomplished by kickdown operation of acceleration pedal I13. Depression of the said pedal beyond wide open throttle position compresses the spring I85 of the lost motion connection I85 and permits movement of lever I18 sufficiently to swing lever I86 to such position that the finger I69 thereof engages the operating finger I31 of switch IfiI. Movement of the finger I61 de-energizes the direct drive coil 56 by opening the circuit between wires I94 and i9! and at the same time energizes underdrive coil 59 through wires I61, I9l, terminals I92, 193 of switch :56, wir I69, switch I62, wire I19, switch I35 and wire I1 l. After the vehicle has been acceleratcd to the desired speed, return to direct drive condition is made by releasing accelerator pedal I13 which will return to throttle closed position under the influence of the spring I16 whereupon the finger $99 of lever I96 will engage the operating finger it? of switch I6! to thereby open the circuit between wires i6! and I 9| and close the circuit between wires i9; and I 9 I.

When the vehicle is brought to a stop, the gOV- ernor mechanism I63 will operate at a speed of approximately 10 M. P. H. to open the circuit between tcrminals I92, I93 of switch I69 and close the circuit between terminals I65, I66 thereof. This will cause unit B to return to underdrive condition of operation and the vehicle may be brought to a stop by application of the brakes with the gear shift lever Mremaining in high speed position. The governor mechanism I 63 operates to return the unit B to underdrive condition at a slower speed than is the case when the change is made from underdrive to direct in unit 13 because of the lag which is inherent in most governor mechanisms when speed thereof is reduced. This condition is a desirable one because it is not desired to change to underdrive in unit B at a speed higher than approximately 10 M. P. H. In some cases it might be desirable to further reduce this speed in order that change to underdrive in unit B wil1 not take place every time the vehicle is slowed down in traffic unless it is slowed down to an extremely slow speed which requires the use of the underdrive mechanism to obtain a smooth pick up to cruising speed.

If the vehicle remains at rest with the gear shift lever 95 at high speed position, there will be a creeping tendency due to the fact that coil 59 remains energized and the amount of torque developed by the engine at idling speed thereof is being transmitted to the tail shaft II. This creeping tendency may be overcome by moving the gear shift lever 95 to neutral position thereupon de-energizing coil 59 through the action of the switch I35. This last action may be accomplished without disengaging sleeve 89 from clutch teeth 81 because of the movement of the finger I46 permitted in the slot I51 of the fork I49 without causing shifting movement of the fork I49 or rail I5I. Thus the vehicle may remain at rest with the rear gearbox C in direct drive condition and the coils 56 and 59 de-energized. The vehicle may be started from rest simply by movement of the gear shift lever 95 to hi h speed position, which action is accomplished quickly and easily by a flick of the finger whereupon coil 59 will be energized and the vehicle may be accelerated smoothly with the unit 13 operating in underdrive and the unit 0 in direct drive. When predetermined speed has been reached a change to direct drive in unit 13 will be accom- 13 plished by operation of the governor switch I60, as described above.

The car may also be held at rest without creep with the sleeve 89 engaged and the gear shift lever 95 in high or low speed position by depressing the pedal I12 to the extent of its movement whereupon the switch I62 will be opened and the coil 59 de-energized. Switch I62 is particularly useful when the car is being maneuvered at relatively slow speeds, for example as when parking. By manipulation of pedal I12 the resistance in the electrical circuit may be varied as desired and an effect similar to feathering of a friction clutch may be obtained.

Reverse operation of the vehicle is obtained by moving the gear shift lever 95 to neutral position and rocking it upwardly of the steering column, thereby to move the shift finger I45 out of engagement with fork I49 and into engagement with fork I59. If sleeve 89 is in either of its engaged positions, it will be automatically cammed back to neutral position by the action of the cam shaped portion I56 of the finger I46 during its movement into engagement with the fork I50.

After the finger I46 has been engaged with the fork I59, swinging of the gear shift lever 95 counterclockwise of the steering column axis will move the idler gear 85 rearwardly of Fig. 7 and into mesh with gears 83 and 84, thereby establishing reverse drive condition in gearbox C. The operation of the underdrive mechanism B is exactly the same in reverse as for forward speeds and a two speed reverse operation may be obtained in the same manner except that the speed at which the governor I63 operates will be somewhat lower due to the fact that the reverse drive rati is relatively low.

When the control mechanism is modified by the substitution of an engine driven governor in place of the pedal I12 a is illustrated in Fig. 16 of the drawings, the operation of the mechanism is substantially the same for all conditions of operation except that the underdrive coil 59 is gradually energized by operation of the overnor I91 upon speeding up of the vehicle motor and is gradually de-energized by operation of the governor when the vehicle is brought to a stop. When the vehicle is at rest, the switch I62 will be open, the governor I91 being adjusted so that this will occur at idling speed of the engine, and thu an automatic no-creep condition is achieved.

Thus it may be seen that We have provided an improved transmission mechanism which is simple in construction and operation and which does not require the acquisition of new driving technique. While only one of the many possible embodiments of the invention hasbeen illustrated and described in this application, it is desired to point out that those skilled in the art will readily perceive that many variations in the mechanism are possible without departing from the spirit of the invention. It is therefore not desired to limit the invention in its broader aspects to the mechanism shown and described herein, except as set forth in the claims appended below.

We claim:

1. I a motor vehicle having an engine, a drive shaft driven by the engine and a driven shaft, means for coupling said shafts together for driving the vehicle comprising an annular member rotatable with said drive shaft and having a cylindrical iron portion; a second annular member rotatable with said driven shaft and having a cylindrical iron portion; means for inducing flow of eddy currents in at least one of said iron portions of said annular iron members during relative'rotation thereof of such strength and direction that said relative rotation is opposed, comprising a stationary core having axially spaced cylindrical pole faces disposed in close radial proximity to and surrounded by said iron portion of one of said annular members and also in substantially radial alignment with the iron portion of the other member such that magnetic flux enters said surrounding iron portions from one of said cylindrical pole faces and returns from said surrounding iron portions to the other of said pole faces, and means for exciting said core.

2. In combination with a drive shaft and a driven shaft, clutch means for drivingly connecting said shafts comprising, an annular member carried by said drive shaft; an annular member carried by said driven shaft; said annular members having portions disposed in radial juxtaposition, a stationary core disposed radially adjacent said portions; a coil for exciting said core; and means operable in response to energization of said coil for producing eddy currents in one of said portions which eddy currents create a flux opposing the flux of said core.

In a drive mechanism, in combination, a rotatable driving member having a cylindrical portion; a rotatable driven member having a cylindrical portion disposed inside the cylindrical portion of said driving member radially adjacent thereto; said driven member cylindrical portion being provided with a smooth inner surface and a toothed outer surface; a stationary field structure including a core and a coil carried thereby, said core having a smooth cylindrical surface portion disposed radially adjacent the smooth surface of said driven member; and means for energizing said field coil to produce flux circulation through said core and said driving and driven cylindrical portions whereby eddy currents are induced in the driving member cylindrical portion during relative rotation of said driving and driven members.

4. The combination set forth in claim 3 wherein the cylindrical portion of said driven member comprises two rings of magnetic material separated by a ring of non-magnetic material and arranged in such manner that the flux passes through on magnetic ring on its way from the core to the driving member and through the other magnetic ring on its return to the core.

5. In an eddy current brake, an annular stationary core member of substantially U-shape having radially oppositely disposed teeth formed in the bifurcated portion thereof; an annular teeth being chamfered along their trailing edges whereby the component of flux tending to produce said eddy currents is substantially increased.

6. In combination, a rotatable driving member; a rotatable driven member; a casing enclosing said members; anv eddy current clutch structure for clutching said members in driving relation; an eddy current brake structure for holding said driven member against rotation; and means for inducing eddy currents in said clutch and brake structures respectively comprising a core mounted in said casing; a pair of field coils carried by said core; means for selectively energizing said coils thereby to produce a pair of magnetic fields, and case for confining the flux paths of said respective fields substantially to the clutch and brake structures r spectively.

7. In an electromagnetic brake, a rotatable member having a brake element carried thereby; a stationary field structure including a core having spaced portions disposed respectively on opposite sides of said brake element; teeth on each of said spaced portions and teeth on said brake element in face-to-face relationship with the teeth of said spaced portions; said teeth on said spaced portions being aligned and spaced such that adjacent teeth thereon are adapted to radially align with adjacent teeth respectively on said brake element.

3. In an electromagnetic clutch, a rotatable driving member having an inner cylindrical peripheral portion; a rotatable driven member having a toothed outer peripheral portion and an inner cylindrical peripheral portion, said toothed portion being disposed radially closely adjacent the inner portion of the driving memher and in substantially radial alignment there with; an annularly shaped field structure including a core having an outer cylindrical portion disposed radially closely adjacent the inner portion of the driven member and also in sub stantially radial alignment with said inner portion of said driving member; and means for energizing the field whereby a selected point on the driving member moves alternately through regions of high and low flux density in response to relative rotation between the members.

9. In a power transmitting means for vehicle drives; drive driven elements and clutch means for drivingly connecting said elements, said clutch means comprising an annular rotor member operably connected to one of said elements, at second annular rotor member operably connected to the other of said elements, each of said members having annular portions of solid iron in radial juxtaposition, a stationary core having axially spaced pole faces disposed within at least one of said annular portions and in substantial radial alignment With the other thereof, a coil for exciting said core, and tooth means carried by one of said members operable in response to energization of said coil, for producing eddy currents in one of said annular iron portions upon rotation of its member which eddy currents produce a flux opposing the flux of said core.

10. Power transmitting means comprising in combination, rotatable drive and driven elements, an eddy current structure for clutching said elements in driving relation, a brake structure for applying braking efiects to one of said elements, said eddy current structure including stationary core means having a cylindrical pole face providing a flux path for said structure, coil means for energizing said flux path, rotatable means having a cylindrical iron portion surrounding said pole face and in radial alignment with said pole face for inducing eddy currents in said clutch structure and means for selectively con trolling operation of said clutch and brake structure.

11. Power transmitting means comprising in combination, a rotatable drive and driven elements, an eddy current structure for clutching said elements in driving relation, an electromagnet structure for applying braking effects to one of said elements, said structure including stationary core means arranged and constructed to provide independent magnetic flux paths for said structures and having at least on cylindrical pole i'ace, coil means for energizing said flux paths independently of each other, rotatable means including cylindrical iron portion surrounding said pole lace and in radial alignment therewith for inducing eddy currents in said clutch structure, and means for selectively controlling energization of said flux paths.

12. Power transmitting means comprising in combination, rotatable drive and driven elements, an eddy current structure for clutching said elements in driving relation, second eddy current structure for applying braking effects to one of said elements, said structures including stationary core means having a plurality of cylindrical pole faces arranged and constructed to provide independent magnetic flux paths for said structures, coil means for energizing said flux paths independently of each other, rotatable means for inducing eddy currents in said structures including iron portions surrounding said pole faces and in radial alignment therewith, and means for selectively controlling energizetion of said flux paths.

13. Power transmitting means comprising drive and driven elements, and clutch means for drivingly connecting said elements, said clutch means comprising an annular rotor member operably connected to one of said elements, a second annular rotor member operably connected to the other of said elements, each of said members having an annular portion of solid iron in radial juxtaposition to each other, a stationary core for providing a magnetic flux path through said iron portions of said members, a coil for exciting said core, and a plurality of axially spaced rows of radial teeth on one of said members operable in response to energization of said coil for producing eddy currents in one of said annular iron portions upon rotation of one of said rotor members which eddy currents produce a flux opposing the flux of said core and serve to clutch said elements in drive.

14. In an electromagnetic clutch, a rotatable driving member having a peripheral iron portion; a rotatable driven member having a peripheral iron portion, one of said iron portions having a series of teeth disposed closely adjacent the other of said iron portions, an annularly shaped field structure including a core having juxtaposed pole faces aligned with the said iron portions of said members whereby the magnetic flux may enter one of said iron portions from one of said pole faces and return from said one iron portion to the other pole lace; and means for energizing the field structure whereby a selected point on the iron portion of one of said members moves alternately through regions of high and low flux density in response to relative rotation between the members.

15. In an electromagnetic brake, a rotatable member having a bral element carried thereby including opposite cylindrical faces, a stationary field structure including cor having radially spaced ylindrical pole faces straddling the cylindric faces of said brake element, teeth on each of said pole faces of said field structure, teeth on said opposite cylindrical faces oi" said brake element, said teeth on said pole faces and element being arranged such that the teeth on one of said pole faces are adapted to be radially 17 aligned with teeth on one of said cylindric faces of said brake element and such that the teeth on the other of said pole faces are adapted to be simultaneously radially aligned with the teeth on the other of said cylindric faces of said brake element.

16. Power transmitting means comprising in combination, rotatable drive and driven elements, an eddy current structure for clutching said elements in driving relation, an electromagnetic structure for applying braking effects to one of said elements, said structures including stationary magnetizable core means arranged and constructed to provide a magnetic path for each of said structures and having at least one cylindrical pole face for each of said structures, coil means for energizing said magnetic paths, rotatable means including cylindrical magnetizable portions at least one of said portions arranged in each of said magnetic paths, means adapted to induce eddy currents in said eddy current structure and means for controlling energization of said magnetic paths.

17. Power transmitting means comprising drive and driven elements and means including an eddy current structure for establishing drive between said elements, said structure comprising a rotor member operably connected to one of said elements, a second rotor member operably connected to the other of said elements, each of said members having a magnetizable portion, stationary means arranged and constructed with magnetizable portions providing magnetic circuit means for the magnetizable portions of said members, and means for energizing said magnetizable portions, said eddy current structure having at least three magnetizable portions in substantial alignment one of which is adapted to induce eddy currents in said structure, and one of said members or means having a plurality of spaced series of teeth with the teeth of one series misaligned with the teeth of the other.

18. Power transmitting means comprising drive and driven elements and means including an eddy current structure for establishing drive between said elements, said structure comprising a rotor member operably connected to one of said elements, a second rotor member operably connected-to the other of said elements, each of said members having a magnetizable portion radially juxtaposed that of the other, and one of said member juxtaposed portions comprising structurally connected sections each provided with a plurality of circumferentially arranged teeth the teeth of one section alternating circumferentially with the teeth of the other section, stationary means arranged and constructed with magnetizable portions providing magnetic circuit means for the magnetizable portions of said members, and means for energizing said magnetizable portions, at least one of said magnetizable portions being adapted to induce eddy currents in said structure in response to relative rotation between said members for clutching said members together in drive.

HENRY W. GILFIILAN. EDGAR L. BAILEY. 

